The present invention relates to thin substrates used in fabricating devices. More particularly, the invention relates to reinforcements for thin substrates.
Thin or ultra thin glass substrates have been proposed for use in fabricating devices. The thin glass substrates are particularly suitable for forming flexible devices, such as organic light emitting diodes (OLEDs). FIG. 1 shows a conventional OLED device 100. The OLED device comprises one or more organic functional layers 110 between first and second electrodes 105 and 115 formed on a thin substrate 101. The electrodes can be patterned to form, for example, a plurality of OLED cells. The cells are used to form a pixelated or segmented OLED device. Bond pads 150, which are coupled to the first and second electrodes, are provided to enable electrical connections to the OLED cells. A cap 160 encapsulates the device to protect the OLED cells from the environment such as moisture and/or air.
To manufacture thin glass substrates, a large sheet of thin glass is first fabricated. The large sheet is then cut to create substrates of the desired size. However, the cutting process may cause defects at the edges of the substrates. These defects make the substrates susceptible to cracking during and after fabrication, thus damaging the devices. This undesirably reduces yields and increase production cost.
As evidenced from the above discussion, it is desirable to provide a thin substrate which is less prone to damage during fabrication of devices.
The invention relates to reinforcements of substrates used in the fabrication of, for example, OLEDs. Such substrates, which are typically made of glass, are brittle and thus are quite susceptible to damage from handling. The reinforcement comprises a support rim at the edge of the substrate. The support rim can be located on the upper, lower, or both surfaces of the substrate. The support rim comprises epoxy, adhesives, or other types of materials which adhere to the substrate. The support rim can be formed using various techniques such as laminating, screen printing, photolithography, dip coating or roll coating.